(183 days)
The ARCHITECT iPhenytoin assay is an in vitro chemiluminescent microparticle immunoassay (CMIA) for the quantitative measurement of phenytoin, an anticonvulsant drug, in human serum or plasma on the ARCHITECT i System with STAT protocol capability. The measurements obtained are used in monitoring levels of phenytoin to help ensure appropriate therapy.
The ARCHITECT iPhenytoin Calibrators are for the calibration of the ARCHITECT i System with STAT protocol capability when used for the quantitative determination of phenytoin in human serum or plasma.
The ARCHITECT iPhenytoin assay is a one-step STAT immunoassay for the quantitative measurement of phenytoin in human serum or plasma using CMIA technology, with flexible assay protocols, referred to as Chemiflex.
Sample, anti-phenytoin coated paramagnetic microparticles, and phenytoin acridinium-labeled conjugate are combined to create a reaction mixture. The antiphenytoin coated microparticles bind to phenytoin present in the sample and to the phenytoin acridinium-labeled conjugate. After washing, pre-trigger and trigger solutions are added to the reaction mixture. The resulting chemiluminescent reaction is measured as relative light units (RLUs). An indirect relationship exists between the amount of phenytoin in the sample and the RLUs detected by the ARCHITECT i System optics.
The acceptance criteria and study proving device performance are described below based on the provided text.
1. Table of Acceptance Criteria and Reported Device Performance
| Acceptance Criteria Category | Reported Device Performance |
|---|---|
| Precision | Substantially equivalent to the AxSYM Phenytoin assay. |
| Linearity | Substantially equivalent to the AxSYM Phenytoin assay. |
| Interferences | Substantially equivalent to the AxSYM Phenytoin assay. |
| Clinical Performance (Correlation to Predicate) | Correlation coefficient of 0.993 with AxSYM Phenytoin assay. |
2. Sample Size Used for the Test Set and Data Provenance
The document does not explicitly state the sample size used for the test set or the data provenance (e.g., country of origin, retrospective or prospective) for the clinical performance study. It only mentions "non-clinical performance data" and "clinical performance data."
3. Number of Experts Used to Establish Ground Truth and Qualifications
This information is not provided in the document. The study compares the ARCHITECT iPhenytoin assay to a legally marketed predicate device (AxSYM Phenytoin assay), implying the predicate's results are used as the reference, rather than independent expert ground truth establishment for a test set in the traditional sense of image analysis or diagnostic interpretation.
4. Adjudication Method
This information is not applicable and not provided in the document. Adjudication methods are typically used in studies involving human interpretation where discrepancies need to be resolved; this study is an analytical performance comparison of an immunoassay.
5. Multi-Reader Multi-Case (MRMC) Comparative Effectiveness Study
No MRMC comparative effectiveness study was mentioned. The ARCHITECT iPhenytoin assay is an in vitro diagnostic device for quantitative measurement of a drug, not a diagnostic imaging or interpretive device that would typically involve human readers.
6. Standalone Performance Study
The entire study described is a standalone performance study in the context of an in vitro diagnostic device. The ARCHITECT iPhenytoin assay's performance (precision, linearity, interferences, and correlation) was evaluated independently and then compared to a predicate device. There is no human-in-the-loop component in the functionality of this immunoassay.
7. Type of Ground Truth Used
The "ground truth" for the clinical performance evaluation was the results obtained from the legally marketed predicate device, the AxSYM Phenytoin assay. The study aimed to demonstrate substantial equivalence by correlating the results of the new device with the predicate.
8. Sample Size for the Training Set
This information is not provided in the document. As an immunoassay, the device relies on chemical and biological reactions rather than machine learning algorithms that typically require dedicated training sets in the computational sense. The "training" for such devices involves assay development and optimization rather than data-driven machine learning training.
9. How the Ground Truth for the Training Set Was Established
Not applicable in the context of an immunoassay. The development and optimization of the ARCHITECT iPhenytoin assay would involve standard laboratory practices to establish parameters (e.g., reagent concentrations, incubation times) that yield accurate and reproducible results, rather than a "ground truth" derived from a training dataset in the machine learning sense. The performance characteristics (precision, linearity, etc.) are established through validation studies.
§ 862.3350 Diphenylhydantoin test system.
(a)
Identification. A diphenylhydantoin test system is a device intended to measure diphenylhydantoin, an antiepileptic drug, in human specimens. Measurements obtained by this device are used in the diagnosis and treatment of diphenylhydantoin overdose and in monitoring levels of diphenylhydantoin to ensure appropriate therapy.(b)
Classification. Class II.